Structure Dynamics Simulation And Analysis Of Gantry Crane

The research and analysis on the metal construction of gantry crane are the most important in the design and manufacture of it. At present, the calculation of the metal construction of gantry crane in different Specifications of different countries mainly adopts static loads. However, with the increasing span of gantry crane and the improvement of speed, the influence of dynamic effect of loads on the structure of gantry crane becomes increasingly apparent. In order to further research the characteristics of the metal construction of large-span gantry cranes as well as its dynamic response characteristics in the process of loading, the present thesis researches the intensity, rigidity, vibration performance, lifting response, seismic response as well as the contact and collision of rails of the crane structure with the help of large-scale finite element analysis software ANSYS and Collision impact simulation software LS-DYNA. The main contents are as follows:1. Static analysis of gantry crane using ANSYS. This paper establishes the finite element modal of the gantry crane, especially the flexible hinge. The loads are determined according to the requirement of Specification. This paper carried out a detailed static analysis of gantry crane under the working condition of stiffness, strength and earthquake. The results show the model meets the design requirements of both static strength and static stiffness.2. Modal analysis and transient analysis of gantry crane using ANSYS. Natural vibration frequency, vibration mode and mode-participation coefficients of gantry crane are generated. The results show that the low order mode of gantry structure will control its seismic vibration, which helps to get the damping value needed in transient analysis. This paper also programs the APDL command stream of gantry crane in lifting and seismic transient analysis.3. Hoisting dynamic characteristics research of gantry crane using ANSYS and APDL. Differential equation of motion of various stages is established, thus getting the time-history tension of steel wire and making the tension continuously stimulate the gantry structure in the form of discrete load. Besides, the vibration condition and stress response condition of gantry crane in the process of lifting are also obtained in the paper. The results show that the equivalent calculation results tend to be unsafe based on Crane Design Specification and the gantry crane is greatly deformed along the trolley track direction.4. Seismic dynamic response study of gantry crane using ANSYS and APDL. The present thesis deduces the vibration analysis model under the stimulus of seismic excitation, selects and adjusts the seismic wave and stimulates the finite element model in the mode of multiple-support excitation, thus getting the seismic dynamic response of gantry crane. Besides, it also analyzes the response law of gantry crane in different wave velocity and traveling wave direction and compares it with the results under consistent input. The results show that it is unsafe, if the seismic load calculated based on Crane Design Specification; traveling wave effect will intensify seismic dynamic response and different wave velocity and traveling wave direction can influence the seismic response of gantry crane.5. Dynamic contact research of the gantry crane wheels using LS-DYNA. According to the current specification requirements, the present thesis establishes the wheel-rail contact model, simulates the dynamic process of wheels when passing through the rail gap and running off to one side and get the contour map and time-history curve of the variation of the distribution of stress in contact area. Results show that there exists penetration in contact area. Besides, the contact spot will change and the stress will increase in dynamic operation. Finally, there also appears no instantaneous detachment between wheel and rail when passing through the rail gap.The content and results of the present thesis can provide some reference for the study of the dynamic characteristics as well as some guidance in the design and manufacture process of the large-span gantry cranes.